Separators For Lithium-ion Batteries Research Articles

Experimental Exploration of Cellulose Material for Battery Separators and Artificial Neural Network-Driven Predictive Modeling for Enhanced Thermal Safety in Electric Vehicles

Abstract Lithium-ion batteries (LIBs) are the most reliable energy storage devices nowadays because of their high energy density, long life cycle, and low self-discharge rate. But still, the safety concern is a significant problem in the area. When talking about LIB safety, thermal effects come first; this leads to thermal runaway, fires, and explosions. The critical component of LIB that has a great role in safety is the separator, which serves the purpose of preventing direct contact between the positive and negative electrodes while enabling the movement of lithium ions. This work aimed to find naturally available cellulose material for the LIB separator and to predict the performance of the material by artificial neural network (ANN) for better control of thermal problems that happen with traditional polymer separator materials. The cellulose derived from banana peels is isolated and characterized for its potential use as a separator material. The study conducts the four selected characterization approaches, scanning electronics microscopy (SEM) with three different resolutions to assess the morphology of the extracted cellulose, differential scanning calorimetry (DSC) to measure the heat flow with temperature change on the cellulose and the value obtained 231.22 J/g at a maximum temperature of 323.18 °C, thermogravimetric analysis (TGA) was used to examine the weight loss of the cellulose with respect to temperature variation, which results in a weight loss of 59.37% when the temperature reaches 235 °C, which is considered favorable, and a differential thermal analysis (DTA) was used to know the temperature difference in the banana peel cellulose (BPC), which results in a temperature of 330.23 °C. This morphological and thermal analysis technique for the BPC is used to determine the heat-related properties of the BPC, including phase transitions, thermal stability, and reaction. In addition, these results show BPC as an alternative material for separators in comparison to the existing polymer-based materials. Furthermore, these experimental results are used to train an ANN to predict the performance of BPC material using a binary classification. Because of the training process, 97.58% accuracy was achieved.

Batch Preparation and Performance Study of Boehmite-Based Electrospun Nanofiber Separators for Lithium-Ion Batteries.

The design and preparation of high-performance separators for lithium-ion batteries (LIBs) have far-reaching practical significance in enhancing the overall performance of LIBs. Electrospun nanofiber separators (ENSs) have the characteristics of large specific surface area, high porosity, small pore size and good affinity with the electrolyte, making them become ideal candidates for LIB separators. In this work, polyacrylonitrile (PAN)/polyurethane (PU) (PAU) ENSs loaded with boehmite (BM) particles (BM/PAU ENSs) were mass-produced using spherical section free surface electrospinning (SSFSE), and used as LIB separators. Their morphology, structures and performances were tested and characterized. The results showed that all BM/PAU ENSs maintained excellent thermal dimensional stability in the range of 140-180 °C, and had good electrolyte wettability and high porosity. The composite BM/PAU-2 ENS with the best performance had a porosity of 52.5%, an electrolyte uptake rate of 822.1%, and an ionic conductivity of 1.97 mS/cm. Additionally, the battery assembled with BM/PAU-2 separator also demonstrated best electrochemical performance, cycling performance, and rate capability, with a capacity retention rate of 94.4% after 80 cycles at 0.5 C, making it a promising high-performance separator for LIBs.

On the strain rate-dependent mechanical behavior of PE separator for lithium-ion batteries

The separator is a critical component for ensuring electrochemical cycling performance and preventing internal short circuits in lithium-ion batteries. For the collision safety of lithium-ion batteries, understanding the rate-dependent mechanical behavior of the separator is essential for battery impact modeling and safety prediction. This study conducts a comprehensive experimental investigation into the strain rate–dependent tensile/compressive behavior and failure mechanism of the polyethylene (PE) separator under quasi-static and dynamic conditions. The combination of deformation images recorded by cameras and post-mortem characterization using SEM was employed to clarify the rate-dependent deformation and fracture mechanism of the separator under both tensile and compressive loading. The experimental results demonstrate a significant strain rate effect on the tensile/compressive mechanical properties and damage/failure behavior of the separator. Furthermore, the effect of the strain rate on the mechanical properties, including the tensile strength, tensile fracture strain, tensile elastic modulus, compressive modulus, yield stress and yield strain of separator, was analyzed and discussed. A significant strain rate-dependent tensile damage and fracture behavior of the separator was observed, where the fracture site exhibited an obvious phase transition and skeletal lamella fracture under extremely high strain rate tensile loading. The separator underwent severe damage under dynamic compressive conditions. The results of this study provide an important basis for the establishment of rate-dependent safety criterion and short circuit prediction of lithium-ion batteries under impact loading, and shed light on understanding separator failure-induced short circuit issues in battery collision safety scenarios.

Efficient mitigation of lithium dendrite by two-dimensional A-type molecular sieve membrane for lithium metal battery

Uneven lithium deposition poses a primary challenge for lithium-ion batteries, as it often triggers the growth of lithium dendrites, thereby significantly compromising battery performance and potentially giving rise to safety concerns. Therefore, the high level of safety must be guaranteed to achieve the large-scale application of battery energy storage systems. Here, we present a novel separator design achieved by incorporating a two-dimensional A-type molecular sieve coating onto the polypropylene separator surface, which functions as an effective lithium ion redistribution layer. The results demonstrated that even after undergoing 1000 cycles, the cell equipped with a two-dimensional A-type molecular sieve-Polypropylene (2D-A-PP) separator still maintains an impressive capacity retention rate of 70 %. In contrast, cells equipped with Polypropylene (PP) separators exhibit capacity retention rates below 50 % after only 500 cycles. Additionally, the incorporation of a two-dimensional molecular sieve enhances the mechanical properties of the PP separator, thereby bolstering battery safety. This study proposes a novel concept for the design of lithium-ion battery separator materials, offering a fresh perspective on the development of separators with exceptional thermal stability, enhanced porosity, superior electrolyte affinity, and effective inhibition of lithium dendrite formation.

Synergy of Silicon-Graphene Anodes and Polymer-Ceramic Hybrid Separators for High Rate-Capable Lithium-Ion Batteries

With more and more electric vehicles (EV) hitting the market, the need for better and more robust energy storage system increases, and silicon has been a promising candidate for the next generation anode material to satisfy the high energy density and high-power requirements for electric vehicles because of its extremely high theoretical capacity. This has allowed the design of thinner electrodes to reduce the diffusion time scales and deliver a fast charge. However, at high charge and discharge rates, low electrical conductivity (~1.12 eV) of silicon hampers the battery performance. As a result, a lot of research has been conducted to improve the performance of silicon anodes using nanoscale carbon to increase the electrical conductivity. Graphene has been used to synthesize Si/Gr hybrid anodes due to its high conductivity.Graphene nanoribbons (GNRs) , a part of the graphene family, are one-dimensional graphene nanostructures which tune its electrical properties based on dimensional confinement. GNR has a higher conductivity than Graphene. It also has high aspect ratio and surface area to provide a strong conductive path along with mechanical strength to support the silicon anode. Due to presence of GNR, lithium-ion transport into silicon nanostructures was enhanced. As a result, 50% of graphene was replaced by 50% GNR with silicon nanoparticles to form anodes. Due to the highly conducting structure of GNR, capacity at high rates was significantly improved because of the improved silicon utilization. Since GNR’s dimensions are in nanometer range, connection with silicon nanoparticles is better. It not only improves silicon to silicon conductivity, but it also acts as a filler for better connection of graphene with silicon nanoparticles.Addition of graphene nanoribbons can improve the lithium-ion transport within the anode but to enhance the high charge transfer rate further, Si/GNR/Gr hybrid, high rate-capable anodes were paired with Polyimide (PI)/Polysilsesquioxane (PSSQ) hybrid separators which also shown to exhibit an improved charge transfer rate. At high rates such as 3C and 5C, the effect of separator on the cell performance becomes more prominent. While Celgard’s performance was very unstable at both 3C and 5C, at 3C, the cycling of hybrid separators did not get impacted, despite the relatively harsher conditions. This synergistic combination of high-rate capable silicon/graphene anode and hybrid separator outperformed the commercially used separator especially at high-rate cycling. Cells with Si/GNR/Gr anode paired with the PI/PSSQ separator delivered an impressive capacity of 1,000 mAh/g at high charge/discharge rates of 5C/5C.

Effects of particle size and flow properties on the performance of ceramic-coated separators in Lithium-ion batteries

This study investigates the relationship between particle size and flow properties of boehmite powders and their impact on ceramic-coated separators for lithium-ion batteries, specifically exploring how these properties influence the performance of the separators. The separators coated with BH-3 powder, with larger sizes and better flow properties than BH-1 and BH-2, showed superior characteristics with the minimum deviation when measuring physical properties such as thickness and roughness. The BH-3 coated separators, with <10% shrinkage at 150 °C for 1 h, showed the highest ion conductivity (0.69 mS cm−1) and superior electrochemical properties compared to bare PE separators. These results highlight the importance of the excellent flow properties of the boehmite powders, which reduces the slurry viscosity, facilitates the formation of a uniform coating layer, and consequently enhances the performance of the separator.

Polyvinylidene fluoride gel‐polyethylene composite separator optimizing the interface compatibility between the separator and the electrode

AbstractThe interface issue concerning lithium dendrite formation between the separator and electrode remains a significant impediment to the further advancement of lithium‐ion batteries (LIB). Due to the inadequate interface compatibility between the conventional polyolefin separator and the electrode, there is a propensity for lithium dendrite growth. In this work, the surface of the polyethylene (PE) separator is coated with polyvinylidene fluoride (PVDF) gel using a simple phase transformation method, resulting in the preparation of a composite separator consisting of PE and PVDF. The results demonstrate an enhanced interface compatibility following the introduction of the gel layer, with a polarization voltage as low as 0.14 V observed after 250 h of cycling. Additionally, the ionic conductivity of the PE/PVDF composite separator (1.77 mS cm−1) is enhanced, attributed to the incorporation of F functional group in PVDF gel, which could facilitate the formation of a rapid ion transport pathway through the interaction between F functional group and Li+. After the introduction of the gel layer, the discharge capacity of the battery after 250 cycles measures ~1.28 mAh, with a mere 27% decay in capacity. This study presents a novel concept for the design of composite separator in LIB.

Rheological and light scattering analyses for characterizing phase separation of polymer solutions in lithium-ion battery separator coating system

Rheological and light scattering analyses for characterizing phase separation of polymer solutions in lithium-ion battery separator coating system

Bismuth oxychloride nanosheets anchored aramid separator with sponge-like structure for improved lithium-ion battery performance

Functional modification of inorganic particles is an effective approach to tackle the issue of Li+ transport and the lithium dendrites formation in lithium-ion batteries (LIBs). In this study, PMIA/BiOCl composite separators are prepared by nonsolvent induce phase separation (NIPS) method using P-type semiconductor bismuth oxychloride (BiOCl) functionalized poly (m-phenylene isophthalamide) (PMIA) separators. Compared with the polypropylene (PP) separator, PMIA has superior thermal stability and the addition of BiOCl further enhances its flame retardancy. And the prepared PMIA/BiOCl separator presents improved porosity (66.47 %), enhanced electrolyte uptake rate (863 %) and higher ionic conductivity (0.49 mS∙cm−1). Besides, the incorporation of BiOCl can anchor PF6- to the three-dimensional network skeleton of the PMIA/BiOCl separators, enabling the desolvation of Li+ and selectively facilitating Li+ transport (the Li+ transfer number is 0.79). Moreover, the uniform porous structure of the PMIA/BiOCl separators and the efficient transport of Li+ uniformly deposite Li+, and minimize the growth of lithium dendrites. Batteries assembled with PMIA/BiOCl separators have a discharge specific capacity of 124.4 mAh∙g−1 and capacity retention of 96.7 % after 200 cycles at 0.2C. Therefore, this work provides an effective route in the design strategy of separators for LIBs.

A novel Al2O3/polyvinyl pyrrolidone-coated polyethylene separator for high-safety lithium-ion batteries

In this study, a novel ceramic-polyethylene (PE) composite separator is designed and achieved by a very facile preparation strategy for high-safety lithium-ion batteries (LIBs). The optimized ceramic slurry composed of Al2O3 and polyvinyl pyrrolidone (PVP) is coated on one side of PE separator in an economically efficient way to form the novel Al2O3/PVP-PE separator. It is found that the superior PVP binder can improve the adherence of heat-resistant Al2O3 ceramic powders on the PE substrate, which significantly enhances the thermal stability of the optimized separator. The Al2O3/PVP-PE separator shows negligible shrinkage at a high temperature of 180 °C after 30 min thermal treatment. In addition, the prepared Al2O3/PVP-PE separator shows excellent wettability with electrolyte, large porosity and high liquid storage capacity, which are quite beneficial to the ionic conductivity and charge storage kinetics. Furthermore, LIBs (LiFePO4/graphite) assembled with the optimized Al2O3/PVP-PE separator shows superior electrochemical performance than LIBs assembled with bare PE separator. This study provides insight into the practical application and commercialization of novel Al2O3/PVP-PE separator for high-safety LIBs with improved electrochemical performance.

The mechanism of in-homogeneous mass transfer process of separators in lithium-ion batteries.

The liquid-phase mass transport is the key factor affecting battery stability. The influencing mechanism of liquid-phase mass transport in the separators is still not clear, the internal environment being a complex multi-field during the service life of lithium-ion batteries. The liquid-phase mass transport in the separators is related to the microstructure of the separator and the physicochemical properties of electrolytes. Here, in-situ local electrochemical impedance spectra were developed to investigate local inhomogeneities in the mass transfer process of lithium-ion batteries. The geometric microstructure of the separator affects the mass transfer process, with a reduction in porosity leading to increased overpotentials. There is a competitive relationship among porosity, tortuosity, and membrane thickness in the geometric parameters of the separator, resulting in a peak of polarization. The resistance of the liquid-phase mass transfer process is positively correlated with the viscosity of the electrolyte, making ion migration difficult due to high viscosity. Polarization is closely related to the electrochemical performance, so a phase diagram of battery performance and inhomogeneous mass transfer was developed to guide the design of the battery. This study provides a guiding basis for the development of high stability lithium-ion batteries.

Electrospun Silicon Dioxide/poly(vinylidene fluoride) Nanofibrous Membrane Comprising a Skin Multicore-Shell Nanostructure as a New High-Heat-Resistant Separator for Lithium-Ion Polymer Batteries.

Porous silicon dioxide (SiO2)/poly(vinylidene fluoride) (PVdF), SiO2/PVdF, and fibrous composite membranes were prepared by electrospinning a blend solution of a SiO2 sol-gel/PVdF. The nanofibers of the SiO2/PVdF (3/7 wt. ratio) blend comprised skin and nanofibrillar structures which were obtained from the SiO2 component. The thickness of the SiO2 skin layer comprising a thin skin layer could be readily tuned depending on the weight proportions of SiO2 and PVdF. The composite membrane exhibited a low thermal shrinkage of ~3% for 2 h at 200 °C. In the prototype cell comprising the composite membrane, the alternating current impedance increased rapidly at ~225 °C, and the open-circuit voltage steeply decreased at ~170 °C, almost becoming 0 V at ~180 °C. After being exposed at temperatures of >270 °C, its three-dimensional network structure was maintained without the closure of the pore structure by a melt-down of the membrane.

Tri-monomer polyamide acid nanofiber separator for safe and high performance lithium-ion batteries

The separators play a crucial role in ensuring the safety of lithium batteries and greatly affect the electrochemical performance of the battery. However, the weak thermal stability and non-polar surface of commercial polyolefin separators severely restrict the development of the high-performance lithium batteries. In this work, we initially proposed polyamide acid (PAA) nanofiber separator with three monomers through a two-step synthesis method, which was prepared by electrospinning. By controlling different processing temperatures, PAA separators containing different amount of carboxyl groups were obtained. PAA separator had better wettability and thermal stability than PE separator. Meanwhile, the electrospinning method brings ultra-high porosity (95.3 %) to the membrane, resulting a much higher electrolyte absorption and retention rate of PAA (initially 3214 %, 240 % at 50 min) compared to PE separator. In particular, carboxyl groups serve as functional groups to provide an electronegative atmosphere, promoting the transport of lithium ion between the anode and cathode, and playing an important role in improving ionic conductivity. Consequently, batteries with PAA-SOH-50 separator showed the best rate charging/discharging performance, maintaining 87.7 % and 73.6 % of its initial capacity at 2.0 C. Moreover, cells with PAA separator exhibited much higher initial discharge capacity (164.3 mAh g−1) than that with PE separator (126.8 mAh g−1). After 100 cycles at 0.5 C, the PAA nanofiber separator achieved an ultralow attenuation rate of only 0.04 % per cycle, which was less than half of the commercial PE separator (0.10 % per cycle). This work provides a new vision for the development of separator materials, revealing the great influence of functional groups, such as carboxyl groups, on the performance of separators, which provides a strong basis for the further research of high-performance separators.

Eco-Friendly Lithium Separators: A Frontier Exploration of Cellulose-Based Materials.

Lithium-ion batteries, as an excellent energy storage solution, require continuous innovation in component design to enhance safety and performance. In this review, we delve into the field of eco-friendly lithium-ion battery separators, focusing on the potential of cellulose-based materials as sustainable alternatives to traditional polyolefin separators. Our analysis shows that cellulose materials, with their inherent degradability and renewability, can provide exceptional thermal stability, electrolyte absorption capability, and economic feasibility. We systematically classify and analyze the latest advancements in cellulose-based battery separators, highlighting the critical role of their superior hydrophilicity and mechanical strength in improving ion transport efficiency and reducing internal short circuits. The novelty of this review lies in the comprehensive evaluation of synthesis methods and cost-effectiveness of cellulose-based separators, addressing significant knowledge gaps in the existing literature. We explore production processes and their scalability in detail, and propose innovative modification strategies such as chemical functionalization and nanocomposite integration to significantly enhance separator performance metrics. Our forward-looking discussion predicts the development trajectory of cellulose-based separators, identifying key areas for future research to overcome current challenges and accelerate the commercialization of these green technologies. Looking ahead, cellulose-based separators not only have the potential to meet but also to exceed the benchmarks set by traditional materials, providing compelling solutions for the next generation of lithium-ion batteries.

High-Safety Lithium-Ion Battery Separator with Adjustable Temperature Function Inspired by the Sugar Gourd Structure.

As the power core of an electric vehicle, the performance of lithium-ion batteries (LIBs) is directly related to the vehicle quality and driving range. However, the charge-discharge performance and cycling performance are affected by the temperature. Excessive temperature can cause internal short circuits and even lead to safety issues, such as thermal runaway. The separator plays a crucial role in protecting the battery from regular operation, preventing direct touch between the cathode and the anode while allowing the transport of lithium ions. In this study, we have designed a thermoregulating separator in the shape of calabash, which uses melamine-encapsulated paraffin phase change material (PCM) with a wide enthalpy (0-168.52 J g-1) to dissipate the heat generated inside the battery promptly. Under extra-long-use conditions, the heat emitted by the battery is absorbed by the PCM without causing a significant temperature rise that triggers thermal runaway. The PCM separator can effectively suppress the temperature increase caused by battery penetration. Due to the unique structure of the PCM, the battery is short-circuited; it can significantly delay the internal temperature rise of the battery and quickly dissipate the heat, which is consistent with the characteristics of natural calabash in nutrient absorption and water diffusion, improving the melting and heat storage efficiency of the PCM. The design of the phase change separator provides an effective reference for overheat protection and improved safety in lithium-ion batteries.

Evaluation of asymmetric poly(vinylidene fluoride)-coated polyimide separator with three-dimensionally homogeneous microporous structure for high-safety lithium-ion battery

Safety hazards associated with separators in lithium-ion batteries are more pronounced in light of the significant improvement of energy density of batteries, hindering their wide application. In this research, asymmetric poly (vinylidene fluoride) (PVDF)-coated polyimide separators with three-dimensionally homogeneous microporous (3DHM API/PVDF) structure are prepared, in which a PVDF layer with a thickness of 6 μm on one side of polyimide. Polyimide, as the base film, has a high heat-resistant temperature which ensures that as-prepared separators will not be shrunk and burned. The coated PVDF layer imparts 3DHM API/PVDF with thermal shutdown function at 175 °C due to the melting of PVDF. The temperature difference between the shutdown and meltdown temperature is over 100 °C, ensuring that the LIB assembled with 3DHM API/PVDF is safe for use. Moreover, the interconnected microporous structure of the separator facilitates the formation of 3D Li+ transport pathways and uniformity of lithium deposition, suppressing lithium dendrite growth. The coin cells assembled by 3DHM API/PVDF exhibit similar electrochemical performance to that of a commercial polypropylene separator at room temperature. Therefore, the novel 3DHM API/PVDF separator may be a promising candidate for a significantly safer LIB.

Tartaric Acid Cross-Linking Polyvinyl Alcohol as Degradable Separators for Rechargeable Lithium Ion Batteries.

The escalating focus on environmental concerns and the swift advancement of eco-friendly biodegradable batteries raises a pressing demand for enhanced material design in the battery field. The traditional polypropylene (PP) that is monopolistically utilized in the commercial LIBs is hard to recycle. In this work, we prepare a novel water degradable separators via the cross-linking of polyvinyl alcohol (PVA) and dibasic acid (tartaric acid, TA). Through the integration of non-solvent liquid-phase separation, we successfully produced a thermally stable PVA-TA membrane with tunable thickness and a high level of porosity. These specially engineered PVA-TA separators were implemented in LiFePO4 (LFP)|separator|Li cells, resulting in superior multiplicative performance and achieving a capacity of 88 mAh g-1 under 5 C. Additionally, the straightforward small molecule cross-linking technique significantly reduced the crystalline region of the polymer, thereby enhancing ionic conductivity. Notably, after cycling, the PVA-TA separators can be easily dissolved in 95 °C hot water, enabling its reutilization for the production of new PVA-TA separators. Therefore, this work introduces a novel concept to design green and sustainable separators for recyclable lithium batteries.

Utilizing methacrylated lignin as a sustainable macro-crosslinker for synthesizing innovative PVA/AMPS composites crosslinked hydrogel nanofibers: A potential application for lithium-ion battery separators

There are significant issues with commercial separators that must be resolved before they can be used in high-energy-density batteries. These problems include low porosity, poor electrolyte wetting, and low mechanical properties. This study presents a facile method for preparing composite crosslinked hydrogel nanofibers of polyvinyl alcohol (PVA) with 2-acrylamide-2-methylpropanesulfonic acid (AMPS) for lithium-ion battery separators by utilizing methacrylated lignin (LMA) as a bio-based crosslinker. Initially, LMA was synthesized by grafting glycidyl methacrylate (GMA) onto lignin via esterification. Subsequently, a crosslinked hydrogel nanofiber membrane (PVA/AMPS-LMA) was electrospun with varying LMA fractions, which were polymerized by combining free radical copolymerization and esterification reactions. The effectiveness of LMA as a crosslinker was assessed against the N, N′-methylene bisacrylamide (MBA). The study showed that using LMA as a crosslinker significantly improved the membrane's properties. The PVA/AMPS-LMA separator displayed superior features such as mechanical strength, thermal stability, porosity, electrolyte uptake, ionic conductivity, and lithium-ion transference number, when compared with PVA/AMPS, PVA, and Celgard separators. Specifically, the PVA/AMPS-LMA separator demonstrated a high mechanical strength of 24.9 MPa, strong thermal stability at 170 °C with no shrinkage, high porosity (84.3 %), and electrolyte uptake (661.4 %). It also exhibited exceptional ionic conductivity (2.75 mS/cm) and a notable lithium-ion transference number (tLi+ = 0.717). In coin batteries, the PVA/AMPS-LMA separator retained over 96 % capacity (142.4 mAh/g) after 200 cycles at 1C. This performance exceeded that of PVA/AMPS, PVA, and Celgard separators, suggesting that PVA/AMPS-LMA separators have the potential to replace their commercial counterparts.

Functionalized γ-Boehmite Covalent Grafting Modified Polyethylene for Lithium-Ion Battery Separator.

In the field of lithium-ion batteries, the challenges posed by the low melting point and inadequate wettability of conventional polyolefin separators have increased the focus on ceramic-coated separators. This study introduces a highly efficient and stable boehmite/polydopamine/polyethylene (AlOOH-PDA-PE) separator. It is crafted by covalently attaching functionalized nanosized boehmite (γ-AlOOH) whiskers onto polyethylene (PE) surfaces. The presence of a covalent bond increases the stability at the interface, while amino groups on the surface of the separator enhance the infiltration of the electrolyte and facilitate the diffusion of lithium ions. The PE-PDA-AlOOH separator, when used in lithium-ion batteries, achieves a discharge capacity of 126 mAh g-1 at 5 C and retains 97.1% capacity after 400 cycles, indicating superior cycling stability due to its covalently bonded ceramic surface. Thus, covalent interface modification is a promising strategy to prevent delamination of ceramic coatings in separators.

Fabrication of rice-straw lignin/polyacrylonitrile composite membrane for lithium-ion battery separator

This study outlines the successful fabrication of composite membrane using rice-straw lignin/polyacrylonitrile (L-PAN) via electrospinning method, and evaluated as a lithium-ion battery separator. L-PANs exhibited higher porosity and superior electrolyte wettability compared to the commercial Celgard 2300. Remarkably, even after exposure to 150 °C for an hour, L-PANs showed minimal changes, whereas Celgard 2300 experienced notable shrinkage. As a separator for Li/LiFePO4 batteries, L-PANs demonstrated outstanding capacity retention of 97.7 % over 200 cycles and superior cycling performance compared to Celgard 2300. Collectively, this research offers a promising approach to valorizing waste rice straw resources and expanding the application of lignin in the field of lithium-ion battery.